Global model runs discussion

[HurricaneWarning92]

One great example is Wilma. I think that if she hadnt stalled over the Yucatan for nearly 2 days, she would have probably come ashore sw Florida as a category 4.

[cycloneye]

The Western Caribbean will be a hot spot in ten days if GFS is right.



Saved image.

[BigA]

The Western Caribbean will be a hot spot in ten days if GFS is right.

The GFS has been rather consistent with lowering pressures in the Western Caribbean starting around September 18. Considering that the best analog year for 2011 may well be 2010, this makes sense as this was about the time Karl and Matthew formed in the western Caribbean, begining the parade of storms in that region.

[LarryWx]

IF the model consensus of bringing down one big sfc high into the NE US and the 12Z GFS in bringing down a 2nd one were to verify, then the teleconnection would be for above avg. activity down below in the W. Caribbean. GOM, and/or off the east CONUS coast. Look at past seasons for proof of this. So, the 2nd half of SEP is liable to be very active in the western basin. Often times in mid to late Sep. and early to mid Oct., it is the strength of the surface highs that come into the NE US that determine how active it gets below them near the CONUS. That is because there foten is a tendency to balance out high pressure to the north with concentrated low pressure below that high pressure due to sfc convergence. JB has talked about this many times. 1947 is a very good example. Look at old surface wx maps from 9-10/1947 and check out how active it was in those areas from mid-Sep to mid-Oct.

[BigA]

12Z Euro also has falling pressures in the western Caribbean from day 8 to 10. Something to keep an eye on because mid to late September is when that area starts.becoming climatologically favored.

[SouthFLTropics]

With the pattern that we have been in I have been thinking that any threat that us in Florida will receive will come from the Western Caribbean later this month or in October. If we start to see some systems firing up over that untapped ocean heat content we could see some problems coming up our way if the troughy pattern persists. What is saving us now may be our enemy later.

SFT

[bigdan35]

I know its the Nogaps but here is the 18z could be the area thats building up behind Maria




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[BigA]

00Z GFS continues the GFS trend lowering of pressures in the western Caribbean in just over a week, with a closed low developing in the 8-9 day timeframe.

GFS 00Z 300 hour forecast (Just for fun)



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[WeatherEmperor]

If you look at the 00Z GFS and 00Z NOGAPS, they both have a developing low pressure area in the SW Caribbean. At around 288hr, the GFS has it near South Florida. It is long range but let's see if this continues in future runs.



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[LarryWx]

IF the model consensus of bringing down one big sfc high into the NE US and the 12Z GFS in bringing down a 2nd one were to verify, then the teleconnection would be for above avg. activity down below in the W. Caribbean. GOM, and/or off the east CONUS coast. Look at past seasons for proof of this. So, the 2nd half of SEP is liable to be very active in the western basin. Often times in mid to late Sep. and early to mid Oct., it is the strength of the surface highs that come into the NE US that determine how active it gets below them near the CONUS. That is because there foten is a tendency to balance out high pressure to the north with concentrated low pressure below that high pressure due to sfc convergence. JB has talked about this many times. 1947 is a very good example. Look at old surface wx maps from 9-10/1947 and check out how active it was in those areas from mid-Sep to mid-Oct.

Folks,
This is a followup to the post I made above prior to the 12Z Euro release. Since then, the 12Z Sat. Euro , 18Z Sat. gfs and 0Z Sun. gfs are being even more insistent on strong and persistent sfc high pressure over the NE US for the period ~9/17-9/23. When sfc high pressure does this, there is a good bit higher than average potential of a TC existing (either from a homegrown system or from one moving into that area) below it near the SE US/FL/E GOM due to a tendency for sfc pressures to fall and concentrate below persistent big highs aided by sfc convergence. Moreover, big persistent highs like this often act as blocks and normally prevent easy recurves/increase the chance for an existing TC to landfall over the SE US. History/analogs tell me all of this.

Stay tuned, folks. There are ominous signs that tell me that the season is likely going to get a good bit more interesting for the CONUS around the 9/18-24 period for the reason noted. IF the model consensus is close to being correct for 9/17-24, we're looking at about as strong and persistent a sfc high pressure pattern over the NE US as one would expect to see in Sep. I would be surprised to see the CONUS not get hit during or near this period. The 0Z GFs actually shows a 9/23 TC landfall over S FL fwiw as noted by the poster above (not at all surprising..I think we're going to see more runs like this in the days to come). This would be a totally different pattern from what has been experienced for much of the season to this point. The cries of "season cancel will likely become a thing of the past.

[BigB0882]

Will surface highs in the NE not allow troughs to swing down and scoop up any hurricanes?

[LarryWx]

Will surface highs in the NE not allow troughs to swing down and scoop up any hurricanes?

The upper patterns that allow for strong and persistent NE surface highs are ridgey. Therefore, there often are no troughs then dipping down to near the SE US to scoop up TC's.

[Vortex]

6Z GFS continues development over the SW carribean in the long range...

[Vortex]

Euro 00z and Nogaps 6z also favor lowering pressures over the SW carribean in 7-10 days..As larry stated It looks quite reasonable that we will see developments over the western carribean over the next few weeks...

[BigA]

00 FIM and FIMY both develop a tropical cyclone in the western Caribbean at around the same time frame as the GFS.

00 Euro continues to show lowering pressures in that region in the 7-10 day period

As we all know, consistency is the key. If models keep showing similar results run after run, it's time to start paying close attention to the Western Caribbean.

[dwsqos2]

Only a stupid monsoon low on the 12Z gfs; the snoozefest of a season will probably continue.

[psyclone]

Only a stupid monsoon low on the 12Z gfs; the snoozefest of a season will probably continue.

ugh. let's hope we don't have another nicole redux. i still don't know why that overhyped mess got a name. the western caribbean is brimming with potential but until something real develops that's all it is. wake me up when we have a real eye to track, something that's been sorely lacking this year.

[CourierPR]

Only a stupid monsoon low on the 12Z gfs; the snoozefest of a season will probably continue.

Go to Twitter and check out Joe Bastardi's comment. I think that will cure your depression.

[cycloneye]

From Dr Jeff Masters:

Most of the models predict the development of a tropical depression or strong tropical disturbance 5 - 6 days from now off the coast of Africa.

[BigA]

12Z Euro is the same story of lowering pressures as the 00Z, but with more conslidation of vorticity in the western Caribbean.

12Z FIM and FIMY both develop an area of low pressure in the central Caribbean in the 7-8 day time frame.